We propose the total synthesis of cyclic adenosine diphosphate ribose (cADPR). We envision a convergent synthesis in which the morpholine- activated phosphoroamidate N,N'-dicyclohexylcarboxamidine salt of adenosine-5-'phosphate is coupled to 2,3,5-tri-O-benzoyl-D-ribose. The protecting groups will be removed and the intermediate cyclized to produce the desired final product, cADPR. The synthetic material will be fully characterized and compared to enzymatically prepared cADPR. PROPOSED COMMERCIAL APPLICATION: Items will be sold to research community via RBI's catalog.